He even managed to tame his pineapple head-high pony tail for the occasion.

It was close going into the third stage of a three round cook-off against South Australia's Laura Cassai but Owens blitzed the Chocolate Ethereal pressure test set by Quay executive chef, Peter Gilmore.

He beat Cassai by just three points.

"I think it was just about beyond my capabilities," Owens told the judges before they tasted his dessert.

"There (were) plenty of times there where I thought, `no this is too much, I've got no hope.'"

But the judges praised the almonds and nougat in Owens' dessert and Gilmore said it was the closest to what he would serve in this own restaurant.

"I am completely overwhelmed with the whole process and I feel on top of the world," Owens said afterwards.

He scored 35 out of 40 to Cassai's 31, and was crowned the winner with a total of 83 points out of 100 to Cassai's 80.

The 24-year-old takes away $250,000, a book deal, a car and the opportunity to cook in some of Australia's top kitchens.

Cassai had a one point lead over Owens going into the final round but the 19-year-old university student had a meltdown when her chocolate wouldn't temper.

Her family and fellow contestants copped it for yelling advice and encouragement, with Cassai telling them to pipe down.

"Please just don't yell at me anymore for the time being," she said, as she dissolved into tears.

Judge George Calombaris marched over to give her a pep talk and she pulled herself together, making a successful second batch of tempered chocolate.

As she presented her dessert she hadn't read the instructions and slapped a chocolate coated nougat log on each plate instead of cutting it up, which made it hard to eat.

The first round of the grand finale kicked off with contestants doing a mystery box challenge except there was no mystery - they got to pick the ingredients they would both use.

Cassai created grilled scampi with anchovy butter with the cook going well except for dropping a hot pan full of garlic on the floor early on. She scored 25 points.

Judge Matt Preston loved the dish, waxing lyrical about being transported to the docks in the south of Italy upon eating Cassai's creation.

Round two saw contestants compete in a chef's table challenge, which in this case meant having their loved ones sitting opposite as they cooked, throwing in annoying comments when they were trying to concentrate.

The worst offender was Cassai's father, with the teen at one point pleading with him to shut up as he was too distracting.

Owens' mum had onlookers in tears when she explained: "My heart is bigger than this whole room right now I am so proud."

Cassai cooked lobster and scallops with mushroom panzanella salad and scored 24, taking her total to 49.

Owens presented his modern take on Lancashire hotpot but he had to leave a planned galette, which then morphed into chips, off the plate after he burnt the potatoes.

He scored 21 and went into the final round one point behind on 48.

Cassai walked away with $20,000 and Emelia Jackson, who bowed out in the semi-final, was awarded $10,000.